硅酸钠对细粒萤石和石英的分散作用机理

针对细粒萤石浮选体系中存在的异相凝聚问题,通过沉降试验、光学显微镜镜下观察、Zeta电位测定、DLVO理论计算及相关溶液化学计算研究了硅酸钠对细粒萤石和石英的分散作用及机理。结果表明,在pH值6~12范围内,萤石分散性能随着pH值增加而逐渐降低,石英保持较好分散状态,混合矿异相团聚现象较明显; 添加硅酸钠可通过SiO(OH)₃^-降低萤石和石英表面电位,增强颗粒间静电排斥力,维持石英分散状态,提高萤石和混合矿的分散性能。上述所有分散体系都符合DLVO理论模型。     

水泥煅烧过程中铅逸放的影响因素

研究了水泥煅烧过程中Pb逸放的几个影响因素.用原子吸收光谱和X射线衍射分析测试水泥熟料中Pb含量及组分变化.煅烧水泥熟料过程中,Pb的逸放率随Pb元素掺入量的增加而增大.适量SO3和P2O5可以提高Pb在熟料中固熔量,减少Pb逸放.氟矿化剂会促进Pb逸放.煅烧温度越高,Pb的逸放率越高.熟料中的Pb富集于中间相,Pb的含量随着硅率的降低而增加.     

复吹转炉应用无氟造渣剂--铁矾土的生产实践

介绍了鞍钢第二炼钢180t复吹转炉应用铁矾土替代萤石造渣工艺可行,对钢水脱[P]、脱[S]影响甚微。每吨钢成本下降3．43元,转炉污水中F^-质量分数下降95％程度。     

离子色谱法测定萤石中氟化钙的含量

应用离子色谱法(ICS)测定萤石中氟化钙的含量。试样经氢氧化钾熔解,定容进行测定。同时进行了熔解试剂时测定结果的影响试验,并进行了一系列仪器测定精度及方法回收率试验。经过试验发现离子色谱法测定萤石中的氟化钙含量具有分析速度快、无干扰、灵敏度高、准确度高等优点,适合于大批量样品的检测,可以大大地提高工作效率。     

New class of high-entropy defect fluorite oxides RE2(Ce0.2Zr0.2Hf0.2Sn0.2Ti0.2)2O7 (RE = Y,Ho, Er,or Yb) as promising thermal barrier coatings

High-entropy ceramics exhibit great application potential as thermal barrier coating (TBC) materials. Herein, a series of novel high-entropy ceramics with RE₂(Ce_0.2Zr_0.2Hf_0.2Sn_0.2Ti_0.2)₂O₇ (RE₂HE₂O₇, RE = Y, Ho, Er, or Yb) compositions were fabricated via a solid-state reaction. X-ray diffraction (XRD) and energy dispersive spectrometry (EDS) mapping analyses confirmed that RE₂HE₂O₇ formed a single defect fluorite structure with uniform elemental distribution. The thermophysical properties of the RE₂HE₂O₇ ceramics were investigated systematically. The results show that RE₂HE₂O₇ ceramics have excellent high-temperature phase stability, high thermal expansion coefficients (10.3–11.7 × 10^?6 K^-1, 1200 ℃), and low thermal conductivities (1.10-1.37 W m^-1 K^-1, 25 ℃). In addition, RE₂HE₂O₇ ceramics have a high Vickers hardness (13.7–15.0 GPa) and relatively low fracture toughness (1.14-1.27 MPa m^0.5). The outstanding properties of the RE₂HE₂O₇ ceramics indicate that they could be candidates for the next generation of TBC materials.     

我国萤石矿资源开发利用“三率”调查与评价

介绍了我国萤石矿资源开采回采率、选矿回收率和综合利用率的"三率"调查结果。我国萤石矿以单一型为主,年采出矿石量6 213.2 kt。大型萤石矿山数量占全国总数的2.29%,小型矿山数占全国总数的84.20%,小型矿山采出矿石量占全国总量的63.80%。我国萤石矿山开采回采率、选矿回收率及综合利用率分别为84.99%、85.61%、72.51%,萤石尾矿利用率平均为45.38%。     

我国萤石矿床特征及资源潜力分析

萤石是一种具有战略意义的非金属矿产资源,萤石资源对国民经济发展意义重大。我国萤石矿按成因类型可分为热液充填型、沉积改造型和伴生型（可细分为沉积变质型和矽卡岩型）三大类型。总结了各成因类型萤石矿床的基本特征,并对其重要找矿远景区进行了地质评价,认为热液充填型萤石矿依然是找矿重点,具有重大找矿潜力。对沉积改造型、沉积变质型和矽卡岩型矿床的萤石资源潜力再评价是发现共（伴）生萤石矿的一个有效途径。     

贵州某萤石矿选矿试验研究及工业生产实践

针对贵州某萤石选矿厂入选矿石性质变化导致选矿生产技术指标恶化的问题,进行了浮选新药剂制度研究,并在选矿工业生产中应用。工业生产获得的指标为:萤石精矿含CaF297.0%、CaCO31.0%、萤石回收率79.62%。与旧药剂制度下选矿厂的生产指标相比,新药剂制度推广后萤石精矿品位提高9个百分点,碳酸钙含量降低5.8个百分点。选矿生产获得了化工级高品质萤石精矿。     

Determination of Oxygen Self-Diffusion Coefficient in Polycrystalline Li2O by Gas-Phase Analysis

The self-diffusion coefficients of the oxygen ion in polycrystalline Li₂O were determined in the range of 874~1,129°C by means of the gas-solid isotope exchange technique where the diffusion coefficient was calculated from the concentration variation of the tracer ¹⁸O in the diffusion atmosphere with assumption of grain-boundary enhanced diffusion. The determined oxygen self-diffusion coefficient was smaller than the previously reported lithium self-diffusion coefficient. The relative diffusivities of the cation and the anion were discussed with respect to the sublattice structure of the antifluorite cubic Li₂O in comparison with the fluorite cubic crystals.     

浅谈世界萤石资源现状及萤石产业发展方向

萤石资源主要分布在环太平洋成矿带,中国是世界上萤石产量最大的国家。中国萤石产业未来的发展方向将向精细化、复合化、轻量化、环保节能循环经济以及为高新技术服务的应用研究开发等方向发展。